<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<style>
			.box{
				width: 500px;
				height: 450px;
				background-color: aqua;
				/* padding-top: 50px; */
				/* border: 1px solid transparent; */
				/* overflow: hidden; */
			}
			.box .one{
				width: 200px;
				height: 200px;
				background-color: chartreuse;
				margin-top: 50px;
				/* position: absolute; */
				/* float: left; */
				display: inline-block;
			}
		</style>
	</head>
	<body>
		<div class="box">
			<div class="one"></div>
		</div>
	</body>
</html>